1. Field of Invention
The disclosure relates to wireless communications, and more specifically to a wireless communication device that is capable performing phase noise compensation prior to signal transmission.
2. Related Art
Wireless communication devices, such as cellular telephones to provide an example, are becoming commonplace in both personal and commercial settings. The wireless communication devices provide users with access to all kinds of information, as well as the ability to communicate with other such devices across large distances. For example, a user can access the internet through an internet browser on the device, download miniature applications (e.g., “apps”) from a digital marketplace, send and receive emails, or make telephone calls using a voice over internet protocol (VoIP). Consequently, wireless communication devices provide users with significant mobility, while allowing them to remain “connected” to communication channels and information.
Wireless communication devices communicate with one or more other wireless communication devices or wireless access points to send and receive data. Typically, a first wireless communication device generates and transmits a radio frequency signal modulated with encoded information. This radio frequency signal is transmitted into a wireless environment and is received by a second wireless communication device. The second wireless communication device demodulates and decodes the received signal to obtain the information. The second wireless communication device may then respond in a similar manner. The wireless communication devices can communicate with each other or with access points using any well-known modulation scheme, including: amplitude modulation (AM), frequency modulation (FM), quadrature amplitude modulation (QAM), phase shift keying (PSK), quadrature phase shift keying (QPSK), and/or orthogonal frequency-division multiplexing (OFDM), as well as any other communication scheme that is now, or will be, known.
During communication, local oscillators within a wireless transmitter and a wireless receiver generate high-frequency sinusoids in order to modulate and demodulate the communicated signals. However, due to imperfections in the local oscillators, an undesired phase component is often introduced to the sinusoids in the form of phase noise that changes over time. Conventional phase noise compensation is performed in the wireless receiver based on communicated pilot symbols. However, the phase noise injected by the transmitter will compound with the phase noise injected by the receiver. This may result in the phase noise fluctuating too quickly for proper compensation by the receiver.